Fork Question

Thargor

I got a cheap 2012 Trek 4500 recently, Im mostly roadbikes but Id like to have a MTB around for a bit of off-road and for commuting on frosty mornings and this was a bit of a bargain. The bike is immaculate with lovely gears and disk brakes however the fork is listed as:

SR Suntour XCM w/30mm stanchions, coil spring & preload, hydraulic lockout, 100mm travel

So obviously its a spring instead of an air chamber yes? The suspension seems very low and doesnt do much when I hop up and down on it or off kerbs, does that mean that the spring is fecked or is there an adjustment screw hiding somewhere that might just need loosening or something like that? It looks like its nearly down all the way to the tyre compared to other peoples pics of the same bike.

The lockout seems to work well for what little travel is there (~1-2 cm) when unlocked so its not me being an idiot there.

Is there anything I can try to free it up or should I just bring it to an LBS and let them do it?

Tony04

Only adjustment on cheap suntours is preload so clockwise adds spring tension which gives a firmer ride and less sag(how much suspension sinks) when using it anticlockwise less spring tension more sag and softer ride.

To be honest preload doesnt do much cheap suntours tend to seize up over time. Best thing to do is spray some mild lube down the stanchions, i personally used weldtite tf2 but there also specific supsension lube spray, wd40 would work fine aswell. If your bring it to a bike shop thats all theyre going to do.

You could get a full service but bike shop would definitely be telling you to buy a new fork as suntours are so cheap anyway.

There are loads of videos online anyway doing full rebuilds of suntours but it is a tricky job

boomdocker

Doubt the LBS will do much, they are a crap fork, full stop.

Thargor

Any clue of the best place where Id get a dirt cheap replacement? Secondhand or whatever as long as its functional...

Lemming

Thargor wrote: »

Any clue of the best place where Id get a dirt cheap replacement? Secondhand or whatever as long as its functional...

Looking at an archived page for that bike (and the specs are pitifully lacking); you'll be needing a fork with a 1/1'8 steerer intended for 26" wheels with Q/R. With those three points in mind second-hand is probably your best bet as finding a more modern 26" fork that is also capable, uses oil/air, with a straight steerer AND Q/R will almost certainly be a near impossible task, if there are any such options catering to Q/R available today.

boomdocker

Wouldn't even bother upgrading to be honest
As lemming says its gonna be hard enough to find a decent fork they are so outdated now
Sell the bike and buy something decent

dave_o_brien

I think this depends on your actual needs. I had that bike before with that fork and it was grand for gentle laps of Ticknock. If all you want is a bike to explore with, I'd just get it serviced. If you actually want to mountain bike with it, you're probably better off getting a better bike due to the difficulties of upgrading.

You could look at something like this:

https://www.wiggle.co.uk/rockshox-30-silver-tk-coil-forks-9mmqr

It's hardly going to turn the bike into something it isn't, and you might look at that as too much investment in the bike, but that's your call.

Tony04

Look on ebay uk dpd parcel wizard over nothing got used here unless you go on the Facebook groups.

For 200€, on the german websites, you can get the mantiou markhor that comes straight steerer 26 and qr. Really good air fork up there with rockshoxs of twice the price. A bargain in terms of what you get and would add hugely to the bike and definitely be of equal value of selling the bike and spending 200€ more on something else, unlees your good wheeler dealer. However it is expensive and you probably wont get your money back on it in terms of selling it used.

Tony04

Also afaik seths bikes havks started out that exact bike and had a fully upgraded version of that frame, if you curoius to see what you can do with it

Thargor

Thanks all, ah its grand this is just a Winter hack for frosty mornings and the odd mud track, theres still a good bit of bounce in it anyway, its actually the most comfortable bike Ive ever ridden and the brakes and shifters are quality.

dave_o_brien

Thargor wrote: »

Thanks all, ah its grand this is just a Winter hack for frosty mornings and the odd mud track, theres still a good bit of bounce in it anyway, its actually the most comfortable bike Ive ever ridden and the brakes and shifters are quality.

Then enjoy it! If it deteriorates, bring it to a decent bike shop and see what they can do. It was plenty of bike a few years ago for beginners, but if you're into road biking, you probably understand the limitations of it more than a non-cyclist. It's mtb's equivalent of an entry level, shimano claris equipped alu frame & fork bike: it's grand and will give you a sense of what mtb'ing's about, but you are more likely to reach it's limitations sooner rather than later.